cc: Remove dangerous LayerImpl::removeFromParent

cc/layer_impl.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYER_IMPL_H_
 #define CC_LAYER_IMPL_H_
 
 #include <public/WebFilterOperations.h>
 #include <string>
 
@@ skipping 47 matching lines @@
     virtual void setOpacityFromAnimation(float) OVERRIDE;
     virtual float opacity() const OVERRIDE;
     virtual void setTransformFromAnimation(const gfx::Transform&) OVERRIDE;
     virtual const gfx::Transform& transform() const OVERRIDE;
 
     // Tree structure.
     LayerImpl* parent() { return m_parent; }
     const LayerImpl* parent() const { return m_parent; }
     const LayerList& children() const { return m_children; }
     void addChild(scoped_ptr<LayerImpl>);
-    void removeFromParent();
+    scoped_ptr<LayerImpl> removeChild(LayerImpl* child);
     void removeAllChildren();
 
     void setMaskLayer(scoped_ptr<LayerImpl>);
     LayerImpl* maskLayer() { return m_maskLayer.get(); }
     const LayerImpl* maskLayer() const { return m_maskLayer.get(); }
 
     void setReplicaLayer(scoped_ptr<LayerImpl>);
     LayerImpl* replicaLayer() { return m_replicaLayer.get(); }
     const LayerImpl* replicaLayer() const { return m_replicaLayer.get(); }
 
@@ skipping 324 matching lines @@
     // Group of properties that need to be computed based on the layer tree
     // hierarchy before layers can be drawn.
     DrawProperties<LayerImpl, RenderSurfaceImpl> m_drawProperties;
 
     DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }
 
 #endif  // CC_LAYER_IMPL_H_